6.8. The TCP Group

6.8. The TCP Group

-- the TCP group
-- Implementation of the TCP group is mandatory for all
-- systems that implement the TCP.
-- Note that instances of object types that represent
-- information about a particular TCP connection are
-- transient; they persist only as long as the connection
-- in question.
tcpRtoAlgorithm OBJECT-TYPE
SYNTAX INTEGER {
other(1), -- none of the following
constant(2), -- a constant rto
rsre(3), -- MIL-STD-1778, Appendix B
vanj(4) -- Van Jacobson's algorithm [10]
}
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The algorithm used to determine the timeout value
used for retransmitting unacknowledged octets."
::= { tcp 1 }
tcpRtoMin OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The minimum value permitted by a TCP
implementation for the retransmission timeout,
measured in milliseconds. More refined semantics
for objects of this type depend upon the algorithm
used to determine the retransmission timeout. In
particular, when the timeout algorithm is rsre(3),
an object of this type has the semantics of the
LBOUND quantity described in RFC 793."
::= { tcp 2 }
tcpRtoMax OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The maximum value permitted by a TCP
implementation for the retransmission timeout,
measured in milliseconds. More refined semantics
for objects of this type depend upon the algorithm
used to determine the retransmission timeout. In
particular, when the timeout algorithm is rsre(3),
an object of this type has the semantics of the
UBOUND quantity described in RFC 793."
::= { tcp 3 }
tcpMaxConn OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The limit on the total number of TCP connections
the entity can support. In entities where the
maximum number of connections is dynamic, this
object should contain the value -1."
::= { tcp 4 }
tcpActiveOpens OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of times TCP connections have made a
direct transition to the SYN-SENT state from the
CLOSED state."
::= { tcp 5 }
tcpPassiveOpens OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of times TCP connections have made a
direct transition to the SYN-RCVD state from the
LISTEN state."
::= { tcp 6 }
tcpAttemptFails OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of times TCP connections have made a
direct transition to the CLOSED state from either
the SYN-SENT state or the SYN-RCVD state, plus the
number of times TCP connections have made a direct
transition to the LISTEN state from the SYN-RCVD
state."
::= { tcp 7 }
tcpEstabResets OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of times TCP connections have made a
direct transition to the CLOSED state from either
the ESTABLISHED state or the CLOSE-WAIT state."
::= { tcp 8 }
tcpCurrEstab OBJECT-TYPE
SYNTAX Gauge
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of TCP connections for which the
current state is either ESTABLISHED or CLOSE-
WAIT."
::= { tcp 9 }
tcpInSegs OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The total number of segments received, including
those received in error. This count includes
segments received on currently established
connections."
::= { tcp 10 }
tcpOutSegs OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The total number of segments sent, including
those on current connections but excluding those
containing only retransmitted octets."
::= { tcp 11 }
tcpRetransSegs OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The total number of segments retransmitted - that
is, the number of TCP segments transmitted
containing one or more previously transmitted
octets."
::= { tcp 12 }
-- the TCP Connection table
-- The TCP connection table contains information about this
-- entity's existing TCP connections.
tcpConnTable OBJECT-TYPE
SYNTAX SEQUENCE OF TcpConnEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"A table containing TCP connection-specific
information."
::= { tcp 13 }
tcpConnEntry OBJECT-TYPE
SYNTAX TcpConnEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"Information about a particular current TCP
connection. An object of this type is transient,
in that it ceases to exist when (or soon after)
the connection makes the transition to the CLOSED
state."
INDEX { tcpConnLocalAddress,
tcpConnLocalPort,
tcpConnRemAddress,
tcpConnRemPort }
::= { tcpConnTable 1 }
TcpConnEntry ::=
SEQUENCE {
tcpConnState
INTEGER,
tcpConnLocalAddress
IpAddress,
tcpConnLocalPort
INTEGER (0..65535),
tcpConnRemAddress
IpAddress,
tcpConnRemPort
INTEGER (0..65535)
}
tcpConnState OBJECT-TYPE
SYNTAX INTEGER {
closed(1),
listen(2),
synSent(3),
synReceived(4),
established(5),
finWait1(6),
finWait2(7),
closeWait(8),
lastAck(9),
closing(10),
timeWait(11),
deleteTCB(12)
}
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The state of this TCP connection.
The only value which may be set by a management
station is deleteTCB(12). Accordingly, it is
appropriate for an agent to return a `badValue'
response if a management station attempts to set
this object to any other value.
If a management station sets this object to the
value deleteTCB(12), then this has the effect of
deleting the TCB (as defined in RFC 793) of the
corresponding connection on the managed node,
resulting in immediate termination of the
connection.
As an implementation-specific option, a RST
segment may be sent from the managed node to the
other TCP endpoint (note however that RST segments
are not sent reliably)."
::= { tcpConnEntry 1 }
tcpConnLocalAddress OBJECT-TYPE
SYNTAX IpAddress
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The local IP address for this TCP connection. In
the case of a connection in the listen state which
is willing to accept connections for any IP
interface associated with the node, the value
0.0.0.0 is used."
::= { tcpConnEntry 2 }
tcpConnLocalPort OBJECT-TYPE
SYNTAX INTEGER (0..65535)
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The local port number for this TCP connection."
::= { tcpConnEntry 3 }
tcpConnRemAddress OBJECT-TYPE
SYNTAX IpAddress
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The remote IP address for this TCP connection."
::= { tcpConnEntry 4 }
tcpConnRemPort OBJECT-TYPE
SYNTAX INTEGER (0..65535)
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The remote port number for this TCP connection."
::= { tcpConnEntry 5 }
-- additional TCP objects
tcpInErrs OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The total number of segments received in error
(e.g., bad TCP checksums)."
::= { tcp 14 }
tcpOutRsts OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of TCP segments sent containing the
RST flag."
::= { tcp 15 }